1. Field of the Invention
The invention relates generally to an improved arrangement for packaging multiple hydrocyclone separators, especially those used for petroleum fluid processing.
2. Description of the Related Art
The overall construction and manner of operation of hydrocyclone separators is well known. A typical hydrocyclone includes an elongated tapered separation chamber or circular cross-section, which decreases in cross-sectional size from a large overflow and input end to an underflow end. An overflow or reject outlet for the lighter fraction is provided at the base of the conical chamber while the heavier underflow or accept fraction of the suspension exits through an axially arranged underflow outlet at the opposite end of the conical chamber.
Liquids and suspended particles are introduced into the chamber via one or more tangentially directed inlets. These are adjacent to the overflow end of the separation chamber to create a fluid vortex therein. The centrifugal forces created by this vortex throw denser fluids and particles in suspension outwardly toward the wall of the conical chamber, thus giving a concentration of denser fluids and particles adjacent thereto, while the less dense fluids are brought toward the center of the chamber. As the denser fluids and particles continue to spiral towards the small end of the conical chamber, the lighter fractions are forced to move by differential forces in the reverse direction towards the reject outlet. The lighter fractions are thus carried outwardly through the overflow outlet. The heavier particles continue to spiral along the interior wall of the hydrocyclone and eventually pass outwardly via the underflow outlet.
The fluid velocities within a hydrocyclone are high enough that the dynamic forces produced therein are sufficiently high to overcome the effect of any gravitational forces on the performance of the device. Hydrocyclones may therefore be arranged in various physical orientations without affecting performance. Hydrocyclones are commonly arranged in large banks of several dozen or even several hundred hydrocyclones with suitable intake, overflow, and underflow assemblies arranged for communication with the intake, overflow and underflow openings respectively of the hydrocyclones.
Earlier separator systems involving large numbers of hydrocyclone separators commonly employed complex systems of intake, overflow, and underflow pipes or conduits which occupied a substantial amount of space and which required costly and complex support structures for the piping systems involved. It is desired to reduce the space occupied by hydrocyclone assemblies and provide a relatively compact arrangement, especially in the petroleum industry, where offshore platform applications and ship-based installations put a premium on space. A compact arrangement would also minimize the cost of the equipment and improve flow distribution to the hydrocyclone inlets.
The inventor has realized that a related limitation of existing hydrocyclone assembly design is that of flow distribution of fluid into the individual hydrocyclones of an assembly where the hydrocyclones are disposed in parallel within a conventional hydrocyclone vessel. In this type of arrangement, exemplified in FIG. 1, the hydrocyclones 18 are all contained within a single vessel 12. Fluid is injected into a chamber 28 of the vessel 12 via a single inlet nozzle 30. As a result of differential pressure, the fluid passes from the chamber 28 into the inlets 31 of the individual hydrocyclones 18. Using current designs, the inlets 31 of the individual hydrocyclones are all disposed at approximately the same longitudinal location within the chamber 28. The concentration of fluid inlets 31 in the same location results in poor fluid distribution that may actually decrease the effectiveness of the hydrocyclone assembly 10 by limiting differential pressure in the area where the inlets 31 are concentrated. It would be desirable to provide improved flow distribution to the hydrocyclone inlets.
One variation of a prior art arrangement of hydrocyclones placed the hydrocyclones in vertically spaced apart layers, with the hydrocyclones of each layer being disposed in radial arranged arrays with common intake, overflow and underflow piping communicating with the hydrocyclones of the several layers. This arrangement saved the floor space area required for the hydrocyclones above the equipment floor while the intake, overflow and underflow piping was installed beneath the floor together with the necessary valves on each unit for adjusting pressures and for isolating individual hydrocyclones.
Alternative forms of modular hydrocyclone separator systems have been devised in an effort to overcome problems with the layered system. These new systems involve vertically disposed, suitably spaced intake, overflow and underflow headers. Individual hydrocyclones are connected to these headers and a positioned in generally vertical planes in substantially horizontal positions, one above the other. Thus, operator control of the system is facilitated and the operation of individual hydrocyclones can be observed.
Prior methods of arranging multiple hydrocyclones have provided only limited results in the goal of reducing the volume of space taken up by the hydrocyclones. U.S. Pat. No. 4,437,984 shows hydrocyclones arranged vertically, with the hydrocyclones parallel to each other. U.S. Pat. No. 4,163,719 shows hydrocyclones stacked in angled vertical arrays, where each hydrocyclone body is roughly parallel to other hydrocyclones in the same vertical array. U.S. Pat. No. 4,019,980 also shows hydrocyclones stacked in angled vertical arrays, where each hydrocyclone body is roughly parallel to other hydrocyclones in the same vertical array, and also shows multiple arrays sharing common input piping. U.S. Pat. No. 5,499,720 shows hydrocyclones arranged in a radial pattern, with the narrowing bodies of the hydrocyclones adjacent to each other.
It is desired to have hydrocyclones packaged as tightly together as possible so as to take up the minimum amount of space. For offshore platform and ship-based installations, volume of space is at a premium and greater efficiencies are desired for the use of a given volume of space.
Hydrocyclone separators are usually conical in shape, with a wide overflow end and a narrowed underflow end. Placing individual hydrocyclone separators parallel to each other requires that the distance between the center of any two hydrocyclones be at a minimum equal to the combined radii of the two hydrocyclones. Where the hydrocyclones may need to be removed for replacement or maintenance, additional spacing is required to allow for free movement of the hydrocyclones, or even for mounting elements. It is desired to reduce the amount of space between hydrocyclones to allow for more hydrocyclones to occupy a given space.